The conjunctiva is the membrane that lines the eyelid and loops back to cover the sclera, the layer covering the eye right up to the edge of the cornea. The sclera provides the eyeball with structural strength and protects against penetration and rupture. There is also a clear layer in front of the iris and pupil, which is referred to as the cornea. It helps protect the eye by keeping small foreign objects and infection-causing microorganisms out and by contributing to the maintenance of the tear film. The Tenon's capsule is underneath the conjunctiva and on top of the sclera. It contains fibroblasts, connective tissue, blood vessels, and collagen.
The white of the eye often becomes unattractive with age, affected with redness or brown and yellow colored spots. Causes can include lack of sleep, a foreign object, dust, dirt, sun damage, or pollution. PAM, or Primary Acquired Melanosis, typically develops in middle-aged or elderly patients. It almost always comprises flat, indistinct areas of conjunctival pigmentation that appear as brown or yellow spots. Certain medications, both systemic and topical, such as epinephrine-containing eye drops, may darken the conjunctiva and cause pigmented nevi, which can also arise from exposure to the industrial or photographic use of silver preparations. Systemic endocrine diseases and hormonal changes, such as those that accompany pregnancy, may lead to additional melanin production that in turn leads to darkening of the skin and even pigmentation on the conjunctiva. Benign conjunctival nevi are common and most often develop during the first decade of life, but can occur later in life to due ultraviolet light sun damage.
The discoloration of the whites of the eyes due to redness from excessive blood vessels can become chronic and can spawn self-consciousness and even social withdrawal. Over-the-counter remedies like Visine® may work if used on a limited basis and if the eyes are otherwise healthy. These “vasoconstrictors” temporarily shrink blood vessels in the white part of the eye. With overuse, however, eyes may exhibit “rebound redness” when the drops are stopped. Moreover, vasoconstrictors have no effect on brown or yellow spots on the conjunctiva.
Until now, the only permanent treatment for the discolored brown or yellow spots or nevi on the conjunctiva has been invasive surgery. This requires a sharp scalpel or scissors to cut and remove the affected conjunctiva, whose epithelial cells ultimately grow back in seven to ten days. More importantly, the invasive surgery includes a risk of cutting into the Tenon's capsule. Resulting damage to the Tenon's capsule can include unsightly scarring from hyperplastic fibroblasts and can induce permanent blood vessel reaction. The latter can lead to the complication of inducing red eyes, even if none existed before surgery. Cutting the Tenon's capsule thus has the counterproductive effect of making patients more self-conscious, which defeats the initial purpose of removing the brown or yellow spots. Moreover, damage to the Tenon's capsule can result in appreciable pain.
Laser surgery is not a viable treatment option for whitening the eye, because it presents too high a risk of elevated temperatures damaging the Tenon's capsule. High frequency ultrasound, which is principally an ablative procedure, is problematic for the same reason. Therefore, a need exists for a better device and method that can more safely whiten the eye than the current invasive surgical process, so that scarring of the Tenon's capsule can be avoided.